Chronic Obstructive Pulmonary Disease
- Caused by emphysema and chronic bronchitis
- Collectively given to emphysema and chronic bronchitis because the airflow is limited most of the time
- Destruction of alveolar walls, with broken air sacs, lungs cannot exchange O2 for CO2 efficiently
- Irreversible lung damage
- Main cause - SMOKING
- Caused by chronic irritation of bronchial tract
- Increases/thickens resp secretions of mucus which interfers with gas exchanges
- Reversible obstructive resp disease
- Bronchial constriction, wheezing, mucosal edema, inflamed resp passages, dyspnea
Relief of Asthma
- STIMULATE SYMPATHETIC SYSTEM
- Uses of medication to relax resp smooth muscles and produce anti-inflammatory effects of resp passageways
Types of Asthma
- Extrinsic (allergic asthma) - pollen, dust, animal dander
- Intrinsic (nonallergic asthma) - chronic/recurrent resp infections, emotional upset, exercise
- Mixed Asthma
Immunoglobin (IgE) antibodies
Produced and attached to mast cells in lung with exposure to extrinsic asthma. Causes external stimuli to bind to the IgE antibody, releasing histamine and other mast cell products.
***DILATORS THEN STEROIDS***
- Consists of upper/lower airways, lungs, and thoracic cavity. Function is to exchange O2 and CO2 from blood in the lungs.
- Any change in resp status has potential to affect every other body system because all cells need adequate supply of O2 for optimal functioning.
Histamines (inflammation effects)
- Highest concentration found in basophils (type of WBC) and mast cells found near capillaries.
- Released in response to injury.
- Stimulates pain receptors in skull.
Histamine Vascular Effects
- Dilation of venules resulting in localized redness (erythema)
- Increase permeability of small blood vessels allows fluid and protein to escape into surrounding tissues resulting in swelling - causes nasal congestion in mucous membranes and causes edema, wheals, hives, itching, pain (too much in compressed area) in skin.
Histamine Extravascular Smooth Muscle Effects
- Contract smooth muscles of intestine, which impact motility - disturbes intestinal activity, less common than bronchial constriction
- Contracts smooth muscles of bronchioles, which impact motility - causes bronchoconstriction, dyspnea, seen commonly in asthma and emphysema
Histamine Cardiac Effects
- Cardiac conduction impaired (histamine shock)
- Cardiac collapse
- Counteract most but not all effects of histamine on body organs and structures
- Used to relieve acute reactions to histamines - urticaria (hives), hay fever (allergies), insect bites, rhinitis, dermatitis.
- Reduce swelling of nasal passages produces by common cold, hay fever, sinusitis, rhinitis, and other resp allergies by causing small blood vessels of nasal membranes to constrict
- Prevent mast cells from releasing their contents
- Receptors can be blocked from interacting with histamine (H1 and H2)
- Absorbed well from intestinal tract and rapidly metabolized by liver
- Available in oral, drops, or spray form
- Example: when you blow and blow your nose, nothing comes out, it is swelling in tissue, which leads to feeling "stuffy."
Adverse Reactions of Antihistamines
- Drowsiness and sedation most common
- Dry mouth (xerostomia) - ***KNOW THIS***
- Nervousness/Insomnia (rare)
- Stimulation rather than sedation (especially in elderly)
Adverse Reactions of Antihistamines to CNS
- Lassitude (condition of weariness or decreased energy) - ***KNOW THIS***
- Schizophrenic-like reactions
- Overdoses may cause involuntary movements
Adverse Reactions of Antihistamines to GI System
- Increased/Decreased appetite
Adverse Reactions of Antihistamines to Hematologic System
- Rare, but severe
- Anemia or breakdown of RBC
- Reduced platelets/WBC
- Bone marros failure
Contraindications, Precautions, Interactions of Antihistamines
Glaucoma, hyperthyroidism, hypertenstion, enlarged prostate, heart disease, ulcers or other stomach problems, stomach or intestinal blockage, liver disease, kidney disease, bladder obstruction, diabetes.
Drug Interactions with Antihistamines
- MAOIs (penelzine-Nardil or tranylcypromine-Parnatel) may prolong and increase effects of some antihistamines
- Phenergan-Zofran may reduce BP and involuntary movements
Pregnancy and Antihistamines
Category B and C drugs, contraindicated with breastfeeding regardless of medication
Adverse Reactions of Decongestants
- Nasal burning, stinging, dryness
- Insomnia/blurred vision
Contraindications, Precautions, Interactions of Decongestants
- Glaucoma, MAOIs (increase/prolong effects), additive sympathomimetic effects
- Overdose can cause "rebound" (opposite of desired effect) nasal congestion and mild stinging sensation when using topical nasal decongestant
- Example: Affrin only to be used for 3 days, or can increase congestion, heart rate, glaucoma.
Natural Alternative to Decongestant
Netty pot and Normal Saline
Sympathomimetics and Xanthine Derivaties (methylxanthines)
Role of Autonomic System
- Sympathetic: causes bronichal smooth muscle dilation
- Parasympathetic: causes bronchial constriction and increased secretion of mucus
- Most are beta-2 receptor agonists
- Used to relieve bronchospasm resp disorders, such as bronichal asthma, chronic bronchitis, and emphysema.
- Clears up symptoms, but increases anxiety, gitters, palpitations, shakes, etc.
- Risk in older adults: cardiovascular and CNS effects ***KNOW THIS***
Bronchodilators Sympathomimetic Beta-Adrenergic Drugs
- Epinephrine (released from adrenal gland)
- Heart rate increases
- Available as oral, injecgtion, or aerosol
: Adrenergic nerves release norepinephrine as the neurotransmitter for the sympathetic nervous system. The sympathetic system activates and prepares the body for vigorous muscular activity, stress, and emergencies. Adrenergic drugs stimulate the adrenergic nerves directly by mimicking the action of norepinephrine or indirectly by stimulating the release of norepinephrine.